Which vestibular test assesses information about the left horizontal semicircular canal independently from the right?

Which vestibular test assesses information about the left horizontal semicircular canal independently from the right?

• A. Caloric
• B. Sinusoidal rotary
• C. Pseudorandom rotary
• D. Dynamic posturography

Answer: (A)

Caloric testing lets you assess unilateral function of the horizontal semicircular canals by stimulating one ear at a time. When warm irrigation is applied to a single ear, endolymph flow increases in that ear’s horizontal canal, producing nystagmus toward the irrigated ear; cool irrigation does the opposite. By irrigating the left ear and then the right ear separately, you can compare the responses to detect asymmetry or unilateral weakness in one canal system. This ear-by-ear approach is why caloric testing provides information about the left horizontal canal independently from the right. Rotational tests, like sinusoidal or pseudorandom chair rotations, stimulate both horizontal canals together and measure overall vestibulo-ocular reflex performance, not one canal in isolation. Dynamic posturography evaluates balance and sensory integration rather than canal-specific end-organ function, so it doesn’t isolate a single canal.

Caloric testing lets you assess unilateral function of the horizontal semicircular canals by stimulating one ear at a time. When warm irrigation is applied to a single ear, endolymph flow increases in that ear’s horizontal canal, producing nystagmus toward the irrigated ear; cool irrigation does the opposite. By irrigating the left ear and then the right ear separately, you can compare the responses to detect asymmetry or unilateral weakness in one canal system. This ear-by-ear approach is why caloric testing provides information about the left horizontal canal independently from the right.

Rotational tests, like sinusoidal or pseudorandom chair rotations, stimulate both horizontal canals together and measure overall vestibulo-ocular reflex performance, not one canal in isolation. Dynamic posturography evaluates balance and sensory integration rather than canal-specific end-organ function, so it doesn’t isolate a single canal.